Claisen Rearrangement

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Claisen rearrangement

[′klā·sən ‚rē·ə′rānj·mənt]
(organic chemistry)
A thermally induced sigmatrophic shift in which an allyl phenyl ether is rearranged to yield an ortho-allylphenol.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Claisen Rearrangement


the migration of an allyl or substituted allyl group in allyl ethers of phenols (1) or enols (2) with the formation, respectively, of ortho-allyl phenols or C-allyl derivatives of keto-enols:

The Claisen rearrangement is widely used in organic synthesis, in particular for the synthesis of natural compounds.

The rearrangement was discovered by the German chemist L. Claisen in 1912.


Organicheskie reaktsii, collection 2. Moscow, 1950. Pages 1–60. (Translated from English.)
The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
Kojic ester 2a-c was prepared via Claisen Schmidt condensation followed by Steglich esterification with isolated kojic acid to yield 3a-c, whereas kojic ester (5a-d) was prepared via kojyl chloride [11] followed by addition of 4a-d to afford 5a-d (70-87%).
5), which should result from the Claisen Rearrangement in HBP-AL [32].
Base catalyzed Claisen condensation of 7a with 4-hydroxy benzaldehyde in presence of LiOH-[H.sub.2]O (Bhagat et al., 2006) gave compound 7b which upon deprotection (Vogel et al., 2008) yielded compound 7 (Scheme 1).
Finally, distillation was continued from a Claisen flask up to 560[degrees]C.
Claisen condensation, Diels-Alder, Grignard, Hoffman rearrangement, Robinson-Schopf, Schotten-Bauman, Swern's oxidation, Ullman Ether synthesis, Williamson synthesis ...
The method is based on reaction of isopropylmagnesium chloride with 3-methyl-2-butenal, Claisen rearrangement of the resulting alcohol via orthoacetate modification, and alkaline hydrolysis of the resulting ester.
This enzyme catalyzes the Claisen rearrangement of chorismate to prephenate in the shikimate pathway, which is the first committed step in the biosynthesis of the aromatic amino acids phenylalanine and tyrosine.
5) of the F.I., it was pointed out from the early stages of its discovery that the first cyclization step resembles the Claisen rearrangement reaction, which is known as a typical sigmatropy reaction.
Kitao, "New thermo-response dyes: coloration by the claisen rearrangement and intramolecular acid-base reaction," Angewandte Chemie--International Edition, vol.
[20] have reported a biogenetic-like synthesis of racemic 1 from o-cinnamylphenols via the dehydrogenation of DDQ, while Subramanian and Balasubramanian [21] have synthesized racemic 1 from 1-arylprop-2-ynyl aryl ether in good yield by a facile Claisen rearrangement.